1. Field of the Invention
The present invention relates to a golf club and, specifically, it relates to a golf club capable of facilitating the replacement of a shaft. The invention also relates to a method for changing the insertion depth of the shaft of such golf club and a method for replacing such shaft.
2. Description of the Related Art
A golf club is constituted of a shaft and a head mounted on the leading end portion of the shaft, with a grip mounted on the base end side of the shaft.
In a conventionally ordinary golf club head, a hosel hole is formed directly in the head, and a shaft is inserted into the hosel hole and is fixed with adhesive. Here, as the adhesive, generally, there is used epoxy-system adhesive. In replacing the shaft, by heating the hosel portion of the head to destroy its texture constituted of epoxy resin hardened material, the shaft can be pulled out.
In such conventionally ordinary golf club head, the insertion depth of the shaft cannot be changed.
As a golf club capable of changing the insertion depth of a shaft case, in Japanese Patent Publication 2010-213859, there is disclosed a golf club in which a substantially cylindrical shaft case is fixed to the leading end of a shaft, the shaft case is inserted into the hosel of the head of the golf club from the upper end side of the hosel, and the shaft case is fixed to the hosel using first and second annular-shaped screw members removably threadedly mounted on the upper end side of the hosel.
In the golf club of the above-cited publication, a spacer is interposed between the lower end of the shaft case and the bottom portion of the hosel, the hosel includes a female screw formed in its inner peripheral surface on such upper end side, the first screw member is threadedly mounted on the upper end of the hosel coaxially with the hosel, the first screw member includes a female screw formed in its inner peripheral surface on the upper end side thereof, and the male screw of the second screw member is threadedly engaged with the female screw of the hosel. By removing the spacer and first screw member and threadedly mounting the second screw member onto the female screw of the hosel directly, the insertion depth of the shaft can be increased.
In the golf club of JP-A-2010-213859, in order to be able to adjust the shaft insertion depth in three or more stages, multiple sets of spacers and screw members are necessary, whereby the cost of the golf club parts is high.